Day- and date-indicating wristwatch



Sept. 8, 1970 B. BOLLEV' DAY AND DATE-INDICATING wRIs'rw Tcfi 3 sn'ee tsasheet- 2- Filed 001;. 7. 1968 INVENTOR Benki min BOl/e Sept. 8, 1970 B. ,BOLLE DAY- AND DATE-INDICATING WRISTWATCH s Shigets-Sheet 5 Filed Oct. 7, 1968 lfiuewron BcnJ'a m/h 501/6 Arm j United States Patent Office 3,527,047. Patented Sept. 8, 1970 3,527,047 DAY- AND DATE-INDICATING WRISTWATCH Benjamin Bolle, Pforzheim, Germany, ass'ignor to Bernhard Forster, Pforzheim, Germany, a firm Filed Oct. 7, 1968, Ser. No. 765,339 Claims priority, application Ggrmany, June 27, 1968,

Int. (:1: G4b 19/24 US. Cl. 5858 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates to an improvement in a dateadvancing device in date-indicating Wristwatches.

Date-advancing devices have been disclosed for wristwatches having a date ring gear, which by means of a pawl is advanced by one tooth pitch every twenty-four hours. Under the action of an additional spring, the pawl advances the date indication by one day. The pawl is 'slidably mounted and has a nose for engaging the respective date tooth, and a stop for engagement by a finger mounted on the drive Wheel. The pawl is displaced by the finger against spring action in such a manner that the pawl nose passes over the date tooth and the subsequent release of the pawl causes the same to return under spring action so that the nose of the rebounding pawl advances the date ring by one tooth and serves at the same time as a stop which limits the movement of the subsequent date tooth.

In a preferred embodiment of said known date-advancing device, the pawl is arcuate and parallel and coplanar relative to the gear ring and formed with successive apertures, which engage successive guide pins or guide rollers so that the pawl is slidable relative to said pins or rollers and pivotally movable about one of said guide pins, the pawl has at one end an inclined step for engagement by the finger, and the pawl is formed at the other end with a hammer head, which is adapted to advance the date ring.

It is an object of the present invention to provide a dayand date-advancing device for dayand date-indicating Wristwatches of the kind defined hereinbefore. The dayand date-advancing device according to the invention is characterized in that the day-advancing operation is derived from the pawl for effecting the date-advancing operation and is preferably effected by a bell-crank lever which is formed with a slot that is engaged by a pin carried by the pawl. This arrangement is unique in that it provides for a fast day-advancing operation whereas the latter operation previously required considerable time.

The desired indication of the desired day of the week in the corresponding window is adjusted in that the hour hand is moved forwardly or backwardly between the 21 and 24 hour positions. A date-correcting operation involving a movement of the winding stem to a special position is then effected to correct the date indication.

The bell-crank lever may be operated by the pawl carrying a pin which engages a slot of the bell-crank lever and.

is spring-urged to slip over one tooth of the day gear and subsequently advances the same suddenly by one tooth.

If an arcuate pawl is used which is parallel and coplanar with respect to the gear ring, and formed with successive apertures, which engages successive guide pins or guide rollers so that the pawl is slidable relative to said pins or rollers and pivotally movable about one of said guide pins, the pawl has at one end an inclined step for engagement by the finger, and the pawl is formed at the other end with a hammer head, which is adapted to advancethe date ring, the pawl may be provided on one side with a pin which engages a slot of the bell-crank lever to impart a pivotal movement thereto so as to effect a day-advancing operation.

An embodiment of the dayand date-advancing device according to the invention is diagrammatically shown in the drawing, in which FIG. 1 is an elevation showing the dayand dateadvancing device during the cocking of the advancing mechanism,

FIG. 2 is an elevation corresponding to FIG. 1 until the beginning of the advancing operation, and

FIG. 3 is an elevation similar to FIG. 1 and showing the device after the advancing operation has been completed.

The drawing indicates the main mounting plate 1 of the watch movement and the date ring 2, with which the pawl 3 cooperates. The latter has at one end an advancing head 5, which is similar to a hammer head and engageable with the date teeth, and at the other end an inclined step 6, with which the driver consisting of a finger 7 cooperates during each revolution. The drive wheel 8 is driven in known manner from the center wheel 10 by an idler wheel 9.

The pawl 3 is formed with successive apertures 11, 12, which engage successive guide pins 13, 14 so that the pawl 3 is movable along said apertures. The pawl 3 is pivotally movable about the pin 14 engaging the guide slot 12. An angled portion 17 of the return spring 16 engages a curved portion 15 of the advancing head 5. Another portion of the return spring 16 is disposed in an undercut recess 18 of the main mounting plate 1 of the watch movement. An abutment pin 19 carried by the main mounting plate 1 is disposed in the recess 18.

The advancing head 5 is formed with a bevel for engaging the teeth of the date ring 2 so that during a date correction the head 5 moving against the advancing direction tilts the pawl 3 out of engagement.

The mode of operation of the pawl 3 is apparent from the drawing. The finger 7 engaging the inclined step 6 initially tilts the pawl 3 about the pin 14 and then displaces the pawl 3 against the action of the spring 16 to a position in which the pawl 3 is in registry with the next date tooth 4. As the drive wheel 8 continues its rotation, the finger 7 moves beyond the step 6 and the spring action returns the pawl 3 in the direction of the arrow. The subsequent rebound of the pawl 3 causes an advance of the date ring 2 by the advancing head 5. This advance is limited to one tooth pitch because the next date tooth 4 engages the advancing head 5 of the pawl 3 when the same has returned to its position of rest. In this way the instantaneous date correction, which takes place every twentyfour hours, is now completed.

According to the invention, the day-advancing operation is derived from the pawl 3 of the date-advancing device shown in FIG. 1 during the return movement of said pawl and is effected by a bell-crank lever 20 having a slot 22, which is engaged by a pin 21 of the pawl 3 to operate the lever 20. A spring 23 causes the bell-crank lever 20 to slip over one tooth of the day gear and then overcomes the retaining notch 25 of the gear 24 and suddenly advances the same by one tooth, as is apparent from FIGS. 2 and 3.

It is also apparent from the drawing that the arcuate pawl 3 is parallel and coplanar with respect to the gear ring 2 and is formed with successive apertures 11, 12, which are engaged by two successive guide pins 13, 14 or guide rollers so that the pawl is displaceable along said apertures and pivotally movable about the guide pin 14. The pawl is provided on one side with a pin 21, which engages the slot 22 in the bell-crank lever to impart a pivotal movement thereto and cause the same to impart a day-advancing operation to the means 24, 25 under the action of the spring 23.

What is claimed is:

1. A date-indicating wristwatch which comprises a frame,

a date ring mounted in said frame and carrying a circular series of teeth, and

means for advancing said date ring by one tooth once in every twenty-four hours, said means comprising a drive wheel mounted in said frame and arranged to perform one revolution in twenty-four hours,

a driver mounted on said drive wheel for rotation therewith,

a pawl having an input end for engagement by said driver once during each revolution of said drive wheel, and an output end for engaging one of said teeth at a time,

said output end being arranged to engage said tooth upon said engagement of said driver with said input end,

spring means arranged to oppose said movement of said pawl under the action of said driver and to efiect a return of said pawl when said driver has disengaged said input end,

said pawl being arranged to rebound upon said return so as to cause said output end to reengage said date ring and advance it by one tooth and to form a stop for the next succeeding one of said teeth,

said wristwatch also comprising day-indicating means carried by said frame, and

day-advancing means carried by said frame and arranged to advance said day-indicating means in response to the operation of said pawl,

said day-advancing means comprising a bell-crank lever mounted in said frame and formed with a slot, and

a pin carried by said pawl and engaging said slot.

2. A wristwatch as set forth in claim 1, in which said day-indicating means comprise a day gear having a series of teeth, and

said day-advancing means comprise a spring acting on said bell-crank lever and causing the same to slip over one of said teeth of said day gear and subsequently to advance the same suddenly by one tooth in response to an operation of said pawl.

3. A wristwatch as set forth in claim 1, in which said driver consists of a finger,

said pawl is arcuate and parallel to and coplanar with said date ring and formed with apertures, and

said input end of said pawl is formed by an inclined step and said output end of said pawl is formed by a hammer head,

guide elements are carried by said frame and engage said apertures to enable a displacement of said pawl along said apertures and a pivotal movement of said pawl about one of said guide elements,

said pin being adapted to impart a pivotal movement to said lever in response to an operation of said pawl.

References Cited UNITED STATES PATENTS 203,640 5/1878 Paddock 5 8-5 8 3,439,493 4/1969 Mutter et a1. 5 85 8 3,451,211 6/1969 Nakagawa 5858 RICHARD B. WILKINSON, Primary Examiner G. H. MILLER, JR., Assistant Examiner 

